content: /*******************************************************************************
   * Copyright 2011, 2012 Chris Banes.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *******************************************************************************/
  package com.handmark.pulltorefresh.library;
  
  import android.annotation.TargetApi;
  import android.content.Context;
  import android.os.Build.VERSION;
  import android.os.Build.VERSION_CODES;
  import android.os.Bundle;
  import android.util.AttributeSet;
  import android.util.FloatMath;
  import android.webkit.WebChromeClient;
  import android.webkit.WebView;
  
  public class PullToRefreshWebView extends PullToRefreshBase<WebView> {
  
  	private static final OnRefreshListener<WebView> defaultOnRefreshListener = new OnRefreshListener<WebView>() {
  
  		@Override
  		public void onRefresh(PullToRefreshBase<WebView> refreshView) {
  			refreshView.getRefreshableView().reload();
  		}
  
  	};
  
  	private final WebChromeClient defaultWebChromeClient = new WebChromeClient() {
  
  		@Override
  		public void onProgressChanged(WebView view, int newProgress) {
  			if (newProgress == 100) {
  				onRefreshComplete();
  			}
  		}
  
  	};
  
  	public PullToRefreshWebView(Context context) {
  		super(context);
  
  		/**
  		 * Added so that by default, Pull-to-Refresh refreshes the page
  		 */
  		setOnRefreshListener(defaultOnRefreshListener);
  		mRefreshableView.setWebChromeClient(defaultWebChromeClient);
  	}
  
  	public PullToRefreshWebView(Context context, AttributeSet attrs) {
  		super(context, attrs);
  
  		/**
  		 * Added so that by default, Pull-to-Refresh refreshes the page
  		 */
  		setOnRefreshListener(defaultOnRefreshListener);
  		mRefreshableView.setWebChromeClient(defaultWebChromeClient);
  	}
  
  	public PullToRefreshWebView(Context context, Mode mode) {
  		super(context, mode);
  
  		/**
  		 * Added so that by default, Pull-to-Refresh refreshes the page
  		 */
  		setOnRefreshListener(defaultOnRefreshListener);
  		mRefreshableView.setWebChromeClient(defaultWebChromeClient);
  	}
  
  	public PullToRefreshWebView(Context context, Mode mode, AnimationStyle style) {
  		super(context, mode, style);
  
  		/**
  		 * Added so that by default, Pull-to-Refresh refreshes the page
  		 */
  		setOnRefreshListener(defaultOnRefreshListener);
  		mRefreshableView.setWebChromeClient(defaultWebChromeClient);
  	}
  
  	@Override
  	public final Orientation getPullToRefreshScrollDirection() {
  		return Orientation.VERTICAL;
  	}
  
  	@Override
  	protected WebView createRefreshableView(Context context, AttributeSet attrs) {
  		WebView webView;
  		if (VERSION.SDK_INT >= VERSION_CODES.GINGERBREAD) {
  			webView = new InternalWebViewSDK9(context, attrs);
  		} else {
  			webView = new WebView(context, attrs);
  		}
  
  		webView.setId(R.id.webview);
  		return webView;
  	}
  
  	@Override
  	protected boolean isReadyForPullStart() {
  		return mRefreshableView.getScrollY() == 0;
  	}
  
  	@Override
  	protected boolean isReadyForPullEnd() {
  		float exactContentHeight = FloatMath.floor(mRefreshableView.getContentHeight() * mRefreshableView.getScale());
  		return mRefreshableView.getScrollY() >= (exactContentHeight - mRefreshableView.getHeight());
  	}
  
  	@Override
  	protected void onPtrRestoreInstanceState(Bundle savedInstanceState) {
  		super.onPtrRestoreInstanceState(savedInstanceState);
  		mRefreshableView.restoreState(savedInstanceState);
  	}
  
  	@Override
  	protected void onPtrSaveInstanceState(Bundle saveState) {
  		super.onPtrSaveInstanceState(saveState);
  		mRefreshableView.saveState(saveState);
  	}
  
  	@TargetApi(9)
  	final class InternalWebViewSDK9 extends WebView {
  
  		// WebView doesn't always scroll back to it's edge so we add some
  		// fuzziness
  		static final int OVERSCROLL_FUZZY_THRESHOLD = 2;
  
  		// WebView seems quite reluctant to overscroll so we use the scale
  		// factor to scale it's value
  		static final float OVERSCROLL_SCALE_FACTOR = 1.5f;
  
  		public InternalWebViewSDK9(Context context, AttributeSet attrs) {
  			super(context, attrs);
  		}
  
  		@Override
  		protected boolean overScrollBy(int deltaX, int deltaY, int scrollX, int scrollY, int scrollRangeX,
  				int scrollRangeY, int maxOverScrollX, int maxOverScrollY, boolean isTouchEvent) {
  
  			final boolean returnValue = super.overScrollBy(deltaX, deltaY, scrollX, scrollY, scrollRangeX,
  					scrollRangeY, maxOverScrollX, maxOverScrollY, isTouchEvent);
  
  			// Does all of the hard work...
  			OverscrollHelper.overScrollBy(PullToRefreshWebView.this, deltaX, scrollX, deltaY, scrollY,
  					getScrollRange(), OVERSCROLL_FUZZY_THRESHOLD, OVERSCROLL_SCALE_FACTOR, isTouchEvent);
  
  			return returnValue;
  		}
  
  		private int getScrollRange() {
  			return (int) Math.max(0, FloatMath.floor(mRefreshableView.getContentHeight() * mRefreshableView.getScale())
  					- (getHeight() - getPaddingBottom() - getPaddingTop()));
  		}
  	}
  }
  